Needle holding dental tool



ci 5 1954 J. B. G11-:RN ETAL 2,690,617 NEEDLE HOLDING DENTAL TooL Filed sept. 15, 1951 nventor Gttcsnegs www Patented Oct. 5, 1954 NEEDLE HOLDING DENTAL TOOL .lames B. Giern, Romeo, and John E. Bakke, Detroit, Mich.

Application September 15, 1951, Serial No. 246,752

2 Claims.

This invention relates to dental tools and, in particular, to tools for use in the making of dental inlays.

In the making of dental inlays, wax impressions are made of a tooth cavity in order to ascertain the form of the cavity and prepare a cast which will accurately fit the cavity. In the making of the wax mold, it has been found convenient to insert phonograph needles in the Wax impression or pattern while it is in the patients mouth. Hitherto, the dentist has found difficulty not only in accurately inserting these needles in the wax impression while it is in the patients mouth, but also in avoiding dropping needles into the patients mouth. The present invention avoids these diiiiculties and enables the tiny wax pattern to be easily handled, either in removing it from the tooth cavity or in placing it in the mold for producing the metal cast on the bench.

One object of this invention is to provide a needle holder for dental inlay work which will firmly hold the needle while it is being positioned in the tooth cavity in the patients mouth, but which will instantly release its grip on the needle after the needle has been imbedded to a sufncient depth in the wax impression or pattern.

Another object is to provide a needle holder for dental inlay work consisting of a handle having a chuck with openings for receiving the needle in various positions of use, and which contains a magnet yieldingly and releasably engaging the needle, so that when the needle has been inserted to a sufficient depth in the wax impression or pattern, the handle may be withdrawn, leaving the needle in position.

Another object is to provide a needle holder for dental inlay work of the foregoing character wherein the magnet is housed in a non-magnetic hollow head having openings therein at various angles permitting the rearward end of the needle to be inserted through one of the openings into magnetic contact with the magnet.

Other objects and advantages will become apparent during the course of the following description of the accompanying drawings, wherein:

Figure 1 is a side elevation of a needle holder for dental inlay impressions or patterns, according to one form of the invention;

Figure 2 is a central vertical section through the needle holder shown in Figure 1, with the magnet partly in side elevation;

Figure 3 is a bottom plan view of the needle holder shown in Figures 1 and 2; and

Figure 4 is a perspective view of the magnet of the tool, after removal of the tool.

Referring to the drawings in detail, Figures 1 and 2 show a needle holder for dental inlay impressions or patterns, generally designated I0, according to one form of the invention as consisting of a tubular handle II terminating in a head or chuck I2 containing a magnet I3. A plug I having a knurled portion I5 and a reduced diameter stern IE is inserted into the upper end of the bore I of the handle II, as by a press fit. The head or chuck I2 iselongated and roughly cup-shaped with a bore I8 receiving the magnet I3 and having a bottom wall I9 against which the lower end of the magnet I3 abuts. The upper end of the head or chuck I2 receives the lower end of the handle II by the press t thereof in the bore I8 after the magnet I3 has been placed in position within the head I2. The lower end of the head I2 is preferably conical as at 20 and contains a longitudinal bore 2I and lateral bore 22 at right angles thereto for releasably receiving a phonograph needle N. An inclined bore 23 is also formed in the lower end of the head I2 and preferably intersects the bores 2i and 22. The bores 2l, 22 and 23 are of such lengths as to open into the lower end of the bore I8 and come into contact with the lower end of the magnet I3. The magnet I3 is of an especially powerful type and is preferably of an aluminum, nickel and cobalt alloy.

In the use of the invention, the dentist inserts a needle end in one of the three bores 2I, 22 or 23 in the head or chuck I2 until the blunt end thereof engages the powerful magnet I3. The latter then holds the needle firmly in position while it is being inserted in the wax impression or pattern in the tooth cavity in the patients mouth.

The dentist then carefully withdraws the tool from the patients mouth, leaving the needle embedded in the mold, since the frictional engagement of the wax of the impression or pattern on the pointed part of the needle N exceeds the magnetic force tending to hold the needle in its respective bore 2 I, 22 or 23. In this manner, any desired number of needles can be inserted to any desired depth and at any desired angle, depending upon which of the bores 2 I, 22 and 23 is used to hold the needle.

'Ihe needles N thus remain fixed in the wax impression or pattern, so that the pattern can then be withdrawn from the tooth cavity and invested in the conventional manner well known to those skilled in the dental art.

What we claim is:

1. A dental tool for temporarily and releasably holding a steel phonograph needle or the like,

said tool comprising an elongated head having an elongated socket therein closed at one end by an end Wall, said end Wall having a needle-holding bore therethrough extending into said socket, said bore being of substantially the same size and shape as the shank of said needle whereby to rigidly but releasably hold said needle in said head, a magnet disposed in said socket having one end disposed adjacent said end Wall and yieldably and releasably engageable With said needle seated in said bore, and an elongated handle having one end seated in said socket in retaining engagement with said magnet.

2. A dental tool for temporarily and releasably holding a steel phonograph needle or the like, said tool comprising an elongated head having an elongated socket therein closed at one end by an end wall, said end Wall having a plurality of needle-holding bores therethrough extending into said socket, said bores being disposed at different angles relatively to the axis of said head, said bores being of substantially the same size and shape as the shank of said needle whereby to rigidly but releasably hold said needle in said head, a magnet disposed in said socket having one end disposed adjacent said end wall and yieldably and releasably engageable with said needle seated in said bore, and an elongated handle having one end seated in said socket in retaining engagement with said magnet.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 512,381 Keyes Jan. 9, 1894 649,234 Chiavaro May 8, 1900 838,383 Clark Dec. l1, 1906 2,550,775 Clark May 1, 1951 

